Marine Produce Australia: Cone Bay Barramundi Aquaculture ...

4. Marine Monitoring Program
Fish-farming operations are presently restricted to the eastern end of the aquaculture lease.
As operations at the western end of the lease are unlikely to recommence in the foreseeable
future, the focus of the revised marine monitoring program is on the eastern part of the
lease. MPA will inform the DoF and the OEPA immediately if sea-cages are re-deployed to the
western end, or anywhere else within the lease.
4.1 Water quality monitoring
4.1.1 Objectives
The objective of the water quality monitoring program is to assess whether the EQC have
been met in the Moderate Ecological Protection Area (MEPA) and at the boundaries of the
High (HEPA) and Maximum Ecological Protection Areas (MaxEPA). The water quality
monitoring program includes the following analytes: total suspended solids (TSS) (organic
and inorganic fraction), biologically available nutrients (dissolved inorganic nitrogen [DIN],
comprising ammonia [NH3] and nitrite+nitrate [NO2 - + NO3 - ]), chlorophyll-a, light attenuation
and dissolved oxygen.
4.1.2 Responsibility
Water quality management shall be the responsibility of the Proponent (Marine Produce
Australia). The work may be delegated to a nominated third party to undertake on behalf of
the Proponent.
4.1.3 Timing
The Cone Bay site experiences two major climatic cycles: the November-March wet season
and the April-July dry season. The winter dry season is characterised by extended periods of
dry sunny weather, while the summer wet season is characterised by frequent rain and
periodic cyclone events.
It is proposed that water quality sampling is conducted at monthly intervals (four times in
total) between June and September to thus capture the winter-spring dry period, and then
again at monthly intervals (four times in total) between December and March to thus capture
the summer-autumn wet period. Sampling will be conducted on an incoming neap tide.
The design, frequency and scope of the water quality monitoring program will be reviewed
after the first two years of implementation in consultation with the OEPA (see Section 6).
4.1.4 Sampling regime
Sampling sites
On each sampling occasion, duplicate water samples will be collected at 13 compliance sites 2
(encompassing five sites within the MEPA and four sites within each of the High and
Maximum Ecological Protection Areas) and eight reference sites (Figure 4.1) 3 . While each of
the duplicate samples will be frozen, only one of the samples will be analysed immediately.
The other sample will be analysed in the event that the EQG is exceeded.
MEPA samples will be collected downstream of the sea-cages at fixed distance intervals (0 m,
10 m, 50 m, 100 m and 200 m). The distance intervals will be positioned along a vector
orientated in the direction of the prevailing current (as indicated by a surface drogue 4 ). The
approach has two purposes: (i) to measure the extent of the contamination gradient (if any)
2 While site Max4 has been included at the boundary of the HEPA/MAXEPA, this site may be characterised by
different water quality given its proximity to a tidal (mangrove dominated) lagoon. Results obtained at this site may
be eliminated from the data if it is found that the lagoon is artificially inflating the nutrient readings.
3 It is noted that a single sample is to be taken at each site. Replication (i.e. multiple samples per site) is not
important in the context of the Cone Bay water quality monitoring program as the program aims to determine if the
EQG have been met at the edge of the respective ecological protection zones. Replication would only be important
where the program aimed to test hypotheses about the extent of differences between sites and/or proximity from
the sea-cages, which is not the aim of this program.
4 Which on an incoming tide, is likely to be in an easterly direction.
14 Oceanica: Marine Produce Australia: Cone Bay Barramundi Aquaculture, Environmental Monitoring & Management Plan